Tikesh Verma , Debasisha Mishra , Michael Tsatsomeros
{"title":"Cayley transform for Toeplitz and dual matrices","authors":"Tikesh Verma , Debasisha Mishra , Michael Tsatsomeros","doi":"10.1016/j.laa.2024.10.007","DOIUrl":null,"url":null,"abstract":"<div><div>Let an <span><math><mi>n</mi><mo>×</mo><mi>n</mi></math></span> complex matrix <em>A</em> be such that <span><math><mi>I</mi><mo>+</mo><mi>A</mi></math></span> is invertible. The Cayley transform of <em>A</em>, denoted by <span><math><mi>C</mi><mo>(</mo><mi>A</mi><mo>)</mo></math></span>, is defined as<span><span><span><math><mi>C</mi><mo>(</mo><mi>A</mi><mo>)</mo><mo>=</mo><msup><mrow><mo>(</mo><mi>I</mi><mo>+</mo><mi>A</mi><mo>)</mo></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>(</mo><mi>I</mi><mo>−</mo><mi>A</mi><mo>)</mo><mo>.</mo></math></span></span></span> Fallat and Tsatsomeros (2002) <span><span>[5]</span></span> and Mondal et al. (2024) <span><span>[15]</span></span> studied the Cayley transform of a matrix <em>A</em> in the context of P-matrices, H-matrices, M-matrices, totally positive matrices, positive definite matrices, almost skew-Hermitian matrices, and semipositive matrices. In this paper, the investigation of the Cayley transform is continued for Toeplitz matrices, circulant matrices, unipotent matrices, and dual matrices. An expression of the Cayley transform for dual matrices is established. It is shown that the Cayley transform of a dual symmetric matrix is always a dual symmetric matrix. The Cayley transform of a dual skew-symmetric matrix is discussed. The results are illustrated with examples.</div></div>","PeriodicalId":18043,"journal":{"name":"Linear Algebra and its Applications","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Linear Algebra and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024379524003860","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let an complex matrix A be such that is invertible. The Cayley transform of A, denoted by , is defined as Fallat and Tsatsomeros (2002) [5] and Mondal et al. (2024) [15] studied the Cayley transform of a matrix A in the context of P-matrices, H-matrices, M-matrices, totally positive matrices, positive definite matrices, almost skew-Hermitian matrices, and semipositive matrices. In this paper, the investigation of the Cayley transform is continued for Toeplitz matrices, circulant matrices, unipotent matrices, and dual matrices. An expression of the Cayley transform for dual matrices is established. It is shown that the Cayley transform of a dual symmetric matrix is always a dual symmetric matrix. The Cayley transform of a dual skew-symmetric matrix is discussed. The results are illustrated with examples.
期刊介绍:
Linear Algebra and its Applications publishes articles that contribute new information or new insights to matrix theory and finite dimensional linear algebra in their algebraic, arithmetic, combinatorial, geometric, or numerical aspects. It also publishes articles that give significant applications of matrix theory or linear algebra to other branches of mathematics and to other sciences. Articles that provide new information or perspectives on the historical development of matrix theory and linear algebra are also welcome. Expository articles which can serve as an introduction to a subject for workers in related areas and which bring one to the frontiers of research are encouraged. Reviews of books are published occasionally as are conference reports that provide an historical record of major meetings on matrix theory and linear algebra.